This invention relates to an apparatus for grounding one or more cables.
Cable assemblies are used to couple various types of electrical components, such as computer systems, peripheral devices, storage systems, servers, and routers, for transmission of electrical signals. Modern electronic devices operate at high frequencies, with signals transferring data and control information being communicated over the cables. The cables serve to isolate the multiple electrical leads that carry the signals, and electrical connectors also help to provide a solid electrical connection from the electrical leads of one cable to an electrical component or another cable.
A common issue associated with the use of cables and electrical connectors is electromagnetic compatibility (EMC). Sources such as other electrical components, power supplies, and the like that are located near or adjacent the electrical connectors, when operated, will generate emissions that include electromagnetic radiation. These emissions may travel through the air and be received by the cabling between electrical components, which may then conduct the emissions to associated electrical components. These emissions may be particularly inconvenient when the resulting interference disrupts, distorts, or otherwise limits or degrades operation of the associated equipment. For example, with regard to signal transmission for audio or video signals, such emissions may interfere with the signal resulting in degraded sound or pictures. Thus, to provide reliable operation, the connections between electronic devices should be designed so that electromagnetic emissions from one device do not interfere with the proper operation of another.
At higher speeds, the rise and fall times of signals are decreased, which leads to increased radiated emissions at higher frequencies. As a result, conventional techniques may not provide sufficient shielding effectiveness and high-frequency current may leak from connectors. The problem of radiated emissions from “leaky” connectors is exacerbated when a large number of such connectors are placed in close proximity to each other, which can occur in systems that utilize multiple electronic rack subsystems having an increased number of nodes and electronic devices. Such systems of multiple racks are widely used throughout the telecommunications, computing, audio, and entertainment industries, and the cabling between the racks, if not grounded, serves to break the shielding effectiveness of each individual rack, thereby allowing emissions from one rack to invade adjacent racks. Thus, as operating speeds continue to increase, and the density of electronic equipment and corresponding connectors increases, protection from radiated emissions provided by conventional shielding designs may not be adequate for satisfactory operation, and the various electrical components of one subsystem may still be affected by the electromagnetic radiation emitted from another subsystem.
Considering the above limitations, the inventors herein have identified a need for an apparatus for grounding a shielded cable that is effective to shield from and to eliminate undesirable emissions from cables as they pass between the electrical components of one electronic subsystem to the electrical components of other electronic subsystems, as well as being easy to manufacture and simple to assemble.